In this study, the effect of oxygen on glucose oxidation using Glucose Oxidase (GOx) and oxygen resistant Pyranose-2-Oxidase (P2O) has been studied. Enzyme solutions with ferrocene carboxylic acid (FcCOOH) as electron mediator were tested with glassy carbon electrode (GCE) under air and nitrogen saturated conditions in a three electrode electrochemical cell system. Electrochemical characterization of enzymes has been achieved in solution by using cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry (CA). In the presence of glucose, CV and LSV results show increasing anodic peak current and decreasing cathodic peak current with increasing glucose concentrations, which reflects the ferrocene-mediated bioelectrocatalysis of glucose oxidation. The experiments with CA show enhanced stability with oxygen resistant P2O where GOx loses 30 % of its current density in the presence of oxygen after 3 hours. These results indicate that P2O, a promising enzyme with no oxygen reactivity and long stability, which can be used in enzymatic biofuel cell applications as an alternative to GOx.
